1. Field of the Invention
The present invention relates generally to integrated circuits, and more particularly but not exclusively to integrated circuit fabrication processes and structures.
2. Description of the Background Art
Capacitors are employed in a variety of integrated circuits, including those that include phase lock loops. Unlike discrete capacitors, capacitors formed in integrated circuits are preferably small to leave more room for transistors and other active components. That is, to conserve die space, it is advantageous to have an integrated capacitor that has relatively large capacitance per unit area.
Various types of capacitors, such as parallel plate, back-end interdigitated, and MOS gate capacitors, have been employed in integrated circuits. However, these capacitors typically require a relatively large area and, depending on the process, additional layers and processing steps. Some of these capacitors are also voltage-dependent, making them unsuitable in applications requiring tight control of capacitance values.